AUS-8 (8Cr13MoV) Steel

[JohnKSa]

Back when I was getting started in knives, AUS-8 was pretty much considered to be a premium knife steel. I still have some knives with AUS-8 blades, and even one with the Chinese equivalent, 8Cr13MoV or 8Cr14MoV.

I've wondered how it stacked up compared to some of the new "supersteels". Dr. Thomas has now answered that question with an article and a video.

Turns out it's still a decent choice--but I don't want to provide too many spoilers.

Testing Chinese Knife Steel 8Cr13MoV/8Cr14MoV - Knife Steel Nerds

New tests of Chinese knife steel 8Cr13MoV, also called 8Cr14MoV. How does it stack up against USA and European steels?

knifesteelnerds.com

 

[hso]

Very interesting


CATRA edge retention



Read the article for more details and conclusions.

Thanks to John for finding the article.

 

[JohnKSa]

An interesting aside from Dr. Thomas' material. It can be difficult to know what you're getting from Chinese steel manufacturers. Some time ago, Spyderco ordered a batch of what was supposed to be 440C and ended up with 8Cr13MoV. They discovered the discrepancy and since the material tested well, they went ahead and used it, but they made sure that the blades were stamped with the correct steel designation.

Years later, Dr. Thomas acquired a bar of what was supposed to be 8Cr13MoV from a source in China for testing and it turned out to be 440C. There are a few videos on Youtube where a reviewer will send various Chinese sourced knives off for analysis to determine if the claimed steel in the blade is accurate. Often it is not.

The moral of the story is that if you buy a Chinese made knife from a Chinese source, you really don't know if you're getting the steel you paid for. On the other hand, if you buy a knife from a reputable company that sources their steel from a Chinese steel provider, you should be ok. As Spyderco did, they should do the due diligence to make sure you get what you paid for.

Anyway, if you have an AUS8 blade, or one that is truly made (and heat treated/tempered properly) from 8Cr13MoV or 8Cr14MoV, it should provide good service. Better than I would have thought.

 

[rhino465]

AUS8 doesn't get nearly enough respect nowadays. Yes, it rusts pretty easily and edge retention isn't great and it's not super tough . . . but it's still pretty good. The great thing about AUS8 is that is so easy to get a thin, incredibly sharp edge with it. A lot of old Spydercos and other good quality knives made with AUS8 are still providing good service.

I know that 8Cr13MoV and 8Cr14MoV are really close to AUS8 in terms of alleged composition, but once the finished product is made, I do not find that knives made from the Chinese alloys share the same sharpening and other characteristics. Logically, that could be because of heat treatment difference, but I would expect Spyderco to shoot for the same ballpark of end result characteristics from them vs. AUS8 of old. There's also the fact (in addition to lies about what it really is) that QA/QC of steel production in Japan is different than their competitors in China. Given the choice, I'd go with AUS8 from Japan every time.

 

[hso]

if you buy a Chinese made knife from a Chinese source, you really don't know if you're getting the steel you paid for

Yep

Before the advent of the high end Chinese manufacturers (Kizer, REATE, WE) it was recognized that the steel claimed wasn't assured other than stainless. Now with the internet market demanding steel specs and anyone willing to get the steel tested can just send a knife off and have the specs back in a couple of weeks (and post it on Social Media) the manufacturers are holding to specs and claims at all but the cheapest level.

 

[JohnKSa]

I know that 8Cr13MoV and 8Cr14MoV are really close to AUS8 in terms of alleged composition, but once the finished product is made, I do not find that knives made from the Chinese alloys share the same sharpening and other characteristics.

Right, they are essentially all the same alloy, just with different designations.

If you're seeing that a knife made from 8Cr13(or14)MoV steel is behaving significantly differently from one made with AUS8, then there are a number of possibilities.

• The geometry of the knife is different enough to alter the characteristics. Dr. Thomas touches on this in the article--it is why he tries to work with steel rather than testing knives.
• The steel isn't really 8Cr13(or14)MoV. As noted, this can be a real issue with the bargain basement Chinese knife makers.
• The heat treatment/temper is different enough to alter the characteristics. That's why you rarely see https://knifesteelnerds.com/ testing knives and almost always starting with steel so they can completely control the heat treat/temper. It is worth noting that the differences in heat/treat/temper could be either due to a intentional attempt to manipulate the steel properties (e.g. improve edge holding at the expense of toughness & ease of sharpening or to improve toughness & ease of sharpening at the expense of edge-holding) or it could be a poor choice by the knife maker.
• There's some sort of significant quality control problem with the steel in question.
• Since these are not CPM steels, there can be "normal" variation of the carbide content/concentration even within a single knife or piece of steel that can significantly alter the sharpening/cutting characteristics of the knife--sometimes even from one sharpening to the next. Dr. Thomas notes a couple of anomalies that came up in testing that he attributed to this issue.

 

[rhino465]

Right, they are essentially all the same alloy, just with different designations.

If you're seeing that a knife made from 8Cr13(or14)MoV steel is behaving significantly differently from one made with AUS8, then there are a number of possibilities.

• The geometry of the knife is different enough to alter the characteristics. Dr. Thomas touches on this in the article--it is why he tries to work with steel rather than testing knives.
• The steel isn't really 8Cr13(or14)MoV. As noted, this can be a real issue with the bargain basement Chinese knife makers.
• The heat treatment/temper is different enough to alter the characteristics. That's why you rarely see https://knifesteelnerds.com/ testing knives and almost always starting with steel so they can completely control the heat treat/temper. It is worth noting that the differences in heat/treat/temper could be either due to a intentional attempt to manipulate the steel properties (e.g. improve edge holding at the expense of toughness & ease of sharpening or to improve toughness & ease of sharpening at the expense of edge-holding) or it could be a poor choice by the knife maker.
• There's some sort of significant quality control problem with the steel in question.
• Since these are not CPM steels, there can be "normal" variation of the carbide content/concentration even within a single knife or piece of steel that can significantly alter the sharpening/cutting characteristics of the knife--sometimes even from one sharpening to the next. Dr. Thomas notes a couple of anomalies that came up in testing that he attributed to this issue.

My first experience with Chinese 8Cr... was with a very early Spyderco Tenacious. That particular knife needed attention to the edge after slicing open a couple of envelopes, both with the factory edge and multiple sharpenings down the road that should have removed any metal that got too hot when the factory ground and sharpened the edge. It reminded me of 420J2 (which is suitable for ornaments and maybe spoons). I think that example had a bad heat treatment, but I had poor luck with subsequent knives as well (and then stopped experimenting). By contrast, I've had only one AUS8 knife that disappointed me (a Camillus folder from a few years before they went out of business).

On an interesting side note, I have a couple of Civivi Praxis folders in 9Cr18MoV that are really, really good. I'm curious if that little extra carbon and other small composition differences really help that much, or if that alloy is more forgiving of heat treatment issues, or WE/Civivi's manufacturing overall is just that good.

 

[hso]

WE/Civivi's manufacturing overall is just that good.

Yep

 

[Jimfern]

I ran across that website last weekend when I was curious about a Kershaw knife I had and was also pleasantly surprised about the quality of that steel. I will say the latest super steels stay sharp a really long time though.

 

[Speedo66]

I’ve noticed many of the Boker knives are AUS-8.

 

[BigBL87]

I’ve noticed many of the Boker knives are AUS-8.

A decent number are, it seemed to be their standard budget/mid-range steel (basically somethin a little nicer than cheap chinese steels). But they've started to shift to D2 to fill that slot more and more it seems. The Kalashnikov line is a good example of that.

 

[RA40]

Interesting, thanks for posting that!
I've been pondering a mid-tier steel and go back forth on the Bohler N690 as well. This grouping with AUS-8/8Cr13 and 440-C these seem to perform similar. Of course for makers finding the steels stateside has challenges as covered in his article. (Looking to find comparable performers.) Glad Larrin posted his HT recipe for his tests, allows me to also suggest this recipe for a heat treat.

 

[westernrover]

I have a Cold Steel blade that's AUS-8. Seeing as how it's not a "utility" knife, I've been quite pleased with the steel. I really never had any issue with it.

For utility knives, the maker's have favored "lesser" steels. For example, I like Mora, Opinel, and Case, none of which come with a steel that's more "super" than AUS-8. Given how I use them, they dull faster than I would like, but I've never had them discolor (Mora's carbon steel, Opinel's Carbone, and Case's Chrome Vanadium will, but their stainless steels are pretty care-free). I find Case's stainless harder to get an edge on, but Opinel's is very easy to sharpen. AUS-8 just doesn't seem to be popular anymore with makers who either persist in using less costly steels or whose customers want steels higher on the charts.

 

[tactikel]

I’ve got 3 older knives in AUS-8. I like it. It takes a keen edge, is tough enough, and is easy to sharpen.

 

[rust collector]

When I see AUS-8 I think of Japanese steel and how they take their steels seriously. To me that means it is more likely to be a known quantity, as opposed to many other products which may be of questionable quality or heat treat.

 

[BigBL87]

When I see AUS-8 I think of Japanese steel and how they take their steels seriously. To me that means it is more likely to be a known quantity, as opposed to many other products which may be of questionable quality or heat treat.

AUS-8 is definitely nothing to sneeze at, definitely a cut above "cheap" and/or unnamed steels. It's just older "tech" at this point, which matters to some but not others. D2 is kinda in that same boat, and it's one of my favorites.

But the heat treat will still vary from brand to brand and what they ask for or do in house. Like with 420HC from Buck vs other brands and even Magnacut between brands (ideal for it is 62.5 HRC per the creator, but some brands only HT to 60-62).

That being said, I'd trust Japanese steel over Chinese (or unknown origin) any day and twice on Sunday.